Chemistry of Life 2.3: Energy, Work, Chemical Reactions, Metabolism

Energy (potential and kinetic)

The capacity to do work

Potential energy is the potential of work being done in the future, stored

Kinetic is active energy, doing work currently

Work

Move something, muscles or molecules,

Chemical reaction

Process in which covalent or ionic bonds are formed or broken

Chemical equation

Showing how the energy is moving

Reactions go on the left, and products go on the right with an arrow pointing towards the right

Decomposition Reactions

Large molecules are broken down into two or more smaller ones AB → A + B

Synthesis Reactions

Two or more small molecules combining into one A + B → AB

Exchange reactions

Two molecules exchange atoms or groups of atoms AB + CD → AC + BD

Reversible reactions

Go in either direction under different circumstances, follows law of mass action

Law of Mass Action

Proceeding from the reactants in greater quantity to the substances with less quantity.

Equilibrium

Ratio of products to reactants is stable

Reaction rates are affected by:

1) concentration: increases when reactants are more concentrated, molecules are more concentrated and collide more frequently

2) temperature: increases as temperature increases, heat causes molecules to move more rapidly and collide with more frequency

3) catalysts: substances that bind to reactants, hold them in position to react with each other

Metabolism (catabolism and anabolism)

Metabolism is all chemical reactions in the body

Catabolism is energy releasing decomposition reactions, break down covalent bonds, produce smaller molecules from larger ones, and release energy to be used in other physiological work

Anabolism is energy storing synthesis reactions, production of fat or proteins

Exergonic vs energonic reactions

Exergonic is energy releasing reactions

Energonic is requiring energy input

Oxidations

Chemical reaction where a molecule gives up an electron and releases energy.

Reduction

Chemical reaction where a molecule gains electrons and energy, when it accepts electrons it is reduced